Given that two foods requiring refrigeration have the same weight and volume and are being shipped from one location to another via the same method, how does the environmental impact of that transportation depend on the type of food being shipped?
Different foods require different refrigeration temperatures and methods, hence the different (energy) costs.
You can transport foods chilled or frozen. The chosen temperature depends on the type of food, travel duration, how long you want to preserve the food, and the desired quality. Some examples; meat and fish are generally kept at temperatures between -18°C and -30°C depending on the type. Many fruits on the other hand are kept just above 0°C because frost causes damage. Some exceptions are oranges which are kept around 5°C and bananas that are stored around 12°C.
Also some foods require special treatment. Butter for example needs to be flash frozen to prevent quality loss.